Anesthesia machines utilizing an anesthetic dispensing device for dispensing a plurality of anesthetics from vaporizers and cylinders have been developed and widely utilized by hospitals. These machines permit administration of a single or mixture of anesthetics to a patient in an oxygen or life-supporting atmosphere with convenience to the anesthesiologist and safety to the patient.
The anesthesia machines should also have the capability of dispensing pure oxygen to the patient and the capability of switching back and forth from anesthetic to oxygen. It is further necessary that the anesthesia machine be designed in such a way that the possibility of contamination of gases and human error is minimized. For example, the machine should provide for the complete separation of the anesthesia gases and minimize contamination therebetween. Further, the machine should provide convenience to the anesthesiologist in preparing for subsequent operations and use.